Oil temperature control valve and cooler



Feb. 6, 1951 L. T. MILLER 2,540,529

OIL TEMPERATURE CONTROL VALVE AND COOLER Original Filed Oct. 31, 1944 7 Sheets-Sheet 2 FIG. 4

E F Ci 50w: m1.

PEG. 5

A 5/ME779L E B D C PEG. 8

2 A Elk/7791.)

INVENTOR Lesnwmmer' BY ATTORKEY Feb. 6, 1951 T. MILLER 2,540,629

on. TEMPERATURE CONTROL VALVE AND COOLER Original Filed Oct. 31, 1944 '7 Sheets-Sheet 5 INVf-INTOR. LesisaTMsHer BY ATTORNEY Feb. 6, 1951 L. T. MILLER 2,540,629

OIL TEMPERATURE CONTROL VALVE AND COOLER Original Filed Oct. 31, 1944 7 Sheets-Sheet 6 VENTOR.

Lesiie .ilier 3/ I ATTORNEY Feb. 6, 1951 L. T. MILLER 2,540,629 I on. TEMPERATURE CONTROL VALVE AND COOLER Original Filed Oct. 31, 194A 7 Sheets-Sheet 7 Pan/pg 1f I: 3:065 EZZ em/g 1 Lil t3 7b 20 l I 0/4 600454? W4zM/NG .sccr/o/v I5 33 I4 I I [A .J mus f", 32 zr/vm/vz 1 II )I v1! I2 I 4- u p r lj if I I l I 1: 1 EAT 33 l9 I [Kill/711111141 v I 0/4 60015,? WARM/N6 SEC) I011! IN VEN TOR.

ATTORNEY Patented Feb. 6, 1951 OIL TEMPERATURE CONTROL VALVE AND COOLER Leslie T. Miller, Stoneleigh, Md., assi'gnor to The Glen L. Martin Company, Middle River, Md., a corporation of Marylmd Continuation of application Serial No. 561,263, October 31, 1944. Thisapplication January 4, 1946, Serial No. 639,091

7 Claims.

Primarily, this invention relates to a method and apparatus for maintaining the oil temperature in thelubricating system of an internal combustion engine system within a narrow range, and more particularly to such a system in which the excessive oil pressures prevailing during the initial starting and warm-up period of the engine are eliminated with respect to the cooler.

This application is' a continuation of application Serial No. 561,263, filed October 31, 1944, now abandoned, which is a continuation-in-part of application Serial No. 414,005, filed October 7, 1941, now Patent No. 2,374,639, dated April 24, 1945.

In operating internal combustion engines, especially aircraft engines, it is essential that the temperature of the lubricating oil in the engine be maintained at a relatively constant temperature for optimum engine operation. Not only must the oil be quickly brought up to this desired temperature, but throughout the flight of the aircraft, it must be maintained and not permitted to become either too hot or too cool.

Another important feature of the present system and apparatus thereof is the substantially complete removal of excessive oil pressures which are prevalent when the oil is cold and the engine is first started up. In modern aircraft, warm-up chambers and oil coolers have been proposed, but due to the inherent construction of conventional oil coolers by which attempts have been made to maintain constant oil conditions, these coolers must not be subjected to pressures in excess of their structural These, structural limits can be increased but at great sacrifice as to weight. Heretofore, the pressures created by the cold oil have oftentimes burst these conventional types of coolers and resulted in great danger to the aircraft and crew.

Among the objects and advantages of the present invention is the complete elimination of these hazards and the precise regulation and control of the oil temperature under all conditions, in-

- eluding initial starting, preliminary warm-up and actual flight.

It has been previously proposed to control oil temperature by a valve located at the inlet to the,

engine, this valve regulating the flow to the oil cooler or to a by-pass line to the oil tank. With such a valve, there is a considerable quantity of oil in the circuit between the oil cooler and the valve, including, as it does, the amount of oil in reduce the oil temperature. This lag results in uneven temperature and may result in a hazardous condition when the heat input from the engine to the oil is suddenly increased tremendously due to a change of operating conditions. By placing a thermostatic element immediately adjacent to the oil cooler, and preferably bolted thereto, this time lag is decreased, and the necessity for an additional line back to the oil tank is eliminated.

This invention contemplates the relieving of dangerous pressures after the engine has been first started, the warming up of the oil returning from the engine to bring it up to operating temperature, and the cooling of the oil should it attempt to exceed the desired temperature. In addition, the system and apparatus permit the automatic warming of the oil if during flight the .cooler lowers its temperature to a degree below that desired for operation.

In the drawings:

Figure 1 is a diagrammatical layout of the system showing a means of controlling the flow of oil during the different periods of operation.

Figure 2 is a basically similar system to Figure 1 with means for circulating the oil through the warming section and through both the warming section and cooling core at a higher temperature.

Figure 3 is also a similar system to that of Figure 1 but having a ressure relief valve therein for further protection against excessive pressures.

Figure 4 is a vertical cross section through a temperature regulating valve of the reciprocating type used to control these several conditions in a system as shown in Figure 1.

Figures 5 and 6 are similar to Figure 4 but showing the sliding regulating valve in varying positions.

Figure 7 is a modification of the lubricating system disclosed in Figure 1 and includes additional ports for circulating the oil from the multiple control valve to the reservoir through a plurality of conduits.

the tank; thus, it should be noted that this quantity of oil must pass through the valve before it can operate to change the amount of cooling to Figure 8 is a modification of the circuit shown in Figure 7 with the additional outlet ports.

Figure 9 is a further modification of the circuit illustrated in Figure 7 embodying the dual oil return system in combination with a pressure relief valve and safety oil circuit.

Figures 10, 11 and 12 are vertical cross sections of, the modified sliding type of control valve used in combination with the dual return lubricating system shown in Figures '7. 8 and 9. Figures 13. 14, and 15 show a turther modified form of temperature controlled valve similar in operation to the valve shown in Figures 4, 5 and 6 but adapted to be rotated by the oil temperature.

Figure 13 is a vertical cross section through this modified valve, while Figures 14 and 15 are vertical, transverse sections taken on lines I4-I 4 and I5I5, respectively, of Figure 13.

Figures 16 and 17 show a further modified form of rotary valve corresponding to the valve illustrated in Figures 10 to 12, inclusive, but using a rotary valve plug instead of a sliding sleeve.

Figure 16 is a vertical, longitudinal cross section of the modified form of rotary valve.

Figure 17 is a vertical, transverse section taken on line I'I--II of Figure 16.

Figures 18 and 19 illustrate the lubricant control system and valve connected to an oil cooler of conventional design having the warming section surrounding the oil cooler core.

Referring nowto Figures 1, 4, 5 and 6 of the drawings, numeral I denotes a multi-port thermostatically controlled valve comprising an outer casing 2 and an inner multi-ported reciprocating sleeve, or cylinder, 3 adapted to receive movement from a thermostatic coil 4 attached to the inner sleeve 3 through linkage mechanism 5. As shown, the oil outlet port G discharges into a conduit 9 leading to an oil tank, or reservoir ID, from there it passes through conduit I I to pump I2 and conduit I3 into an engine I4, from the engine back to the inlet port A of the control valve I through conduit I5.

An oil cooler core I9 of suitable capacity and thermal characteristics is joined to the control valve I and port F thereof by conduit Il, while the opposite side of the oil cooler core is provided with conduit I8 in communication with an oil cooler warming section 20 having a conduit 2| leading to port D. The conduit I8 is also joined to the control valve and port E thereof through conduit 25. A by-pass line 23 joins ports C and B.

The sequence of operation of these several ports is controlled through the inner sliding valve sleeve 3 acting under the influence of the thermostatic device 4, and the particular flow through these ports will now be described in detail.

When starting up, the engine I4 is cold as is the oil supply in the system, including the tank II). It will be obvious that if this high viscosity cold oil is permitted to circulate through the oil cooler core I9, or through warming section 29, the resistance built up in the system will be of such magnitude that there is great danger of rulpturing the cooling elements of the cooler. Consequently, due to the action of the thermostatic device 4, the control valve I, in the position shown in Figure 4, permits the cold oil to enter port A and freely pass out through port B through conduit 23 back into the valve through port C and be discharged therefrom through port G into the reservoir I0. It will be observed from Figure 4 that in this position, when the engine is first started, that ports D and F, leading to the warming section and the core of the cooler, respectively, and the port E, connected to the return conduit from the cooler, are closed so that excessive oil pressures are eliminated with respect to the cooler. Thus, during the initial start-up period when the oil is cold, it is permitted to pass through the system without undue restriction and without building up substantial pressures to thus completely eliminate its passage through either cooler core I9 or' oil cooler warming section 20.

As the oil temperature starts to rise due to heat absorbed thereby from the engine II, the temperature responsive element 4 moves the valve sleeve 3 to close on ports B and C and open ports D and E, as shown in Figure 5. In this position port F remains closed. When this occurs, the oil enters port A and flows out through port D into conduit 2I and passes through the oil cooler warming section 20, which in practice as..shown in Figure 18, is combined with the oil cooler core I9 and forms in efiect an oil cooler assembly, and thence through conduit 25 to port E to be discharged through outlet port G.

As the oil temperature further increases and reaches the desired operating temperature, the thermostatic device moves to the position shown in Figure 6 in such a manner as to close port D and open port F. In this position ports B and C remain closed. When the valve is in this position, oil enters the port A, flows through port F, returns through the oil cooler core I9, through conduits I8 and 25 to port E from whence it passes through the open tubular portion of the valve and outlet G.

The system illustrated in Figure 2 is quite similar to that described in explaining the operation of Figure 1. Themajor difference and furtherance of the present novel lubricating system shown in this figure is the means by which the oil cooler core and oil cooler warming section may be connected to the control valve in such a manner that the oil may selectively flow through the warming section at one temperature and through both the warming section and cooling core at a higher temperature.

With the arrangement of Figure 2, the oil cooler core I9 is joined to the control valve I and port F thereof by conduit I I, while the other side of the cooler core is connected by conduit 24 leading to the warming unit 29 and thence through conduit 25 to port E. The conduit 24 also communicates with the control valve port -D by jointure with conduit 26.

In operation, as the oil temperature in the system starts to rise due to heat absorption from the initial operating period of the engine II, the temperature responsive element 4 moves the inner valve cylinder 3 to close off ports B and C while opening ports D and E. When this occurs, the preliminarily heated oil enters port A through conduit I5 and flows around the valve cylinder and out through port D into conduits 26 and 24 through the warming section 20 and thence through conduit 25 to port E when it is discharged in the central bore of the valve and flows out of the valve through port G to the line 9 runnin to tank I0.

Afte the oil temperature rises and assumes the desired predetermined operating temperaature, the thermal operator 4 moves the sleeve 3 to close port D and open port F. In this position, oil enters port A, flows around the sleeve and out through port F, then to the cooler core I9 through conduit 24 to the warming section 20, through conduit 25 to port E and thence into the central tubular bore of the valve and through discharge outlet G.

Figure 3 carries the improved lubricating system of Figure 1 further by adding the pressure relief valve 21 into the inlet line I5 and outlet line 9, whereby oil is relieved through conduit 28, relief valve 21 and conduit 29. Thus, if excessive pressures for any reason build up between inlet oil at port A and outlet port G, it may reach the relief valve and be by-passed around the control valve directly to reservoir ll. While the relief valve 21 has been shown external to the valve casing, it is obvious that it may be incorporated in the casing if so desired so long as it is capable of communication with port A and p rt G.

The modified systems shown in Figures 7, 8 and 9, together with the modified multi-port sliding control'valve illustrated in Figures 10, l1 and 12, are fundamentally the same as the systems and control valve previously described in Figures 1, 2 and 3, and 4, 5 and 6. respectively.

The purpose of these modified systems is to readily control the oil under the conditions of starting and flight as above described with the added feature of control when it is desired that the oil lead to different sections of the oil tank. Under certain conditions, this further control is an advantage, and to accomplish the same, the control valve l is provided with additional ports H and J. The casing 2 and the inner sliding cylinder 3 are also modified at portions and 3!, respectively, see particularly Figures '7, 10, 11 and 12.

The reciprocating control valve in these figures performs the functions and Operations of the valve shown in Figures 4. 5 and 6, although instead of allowing the oil to flow through outlet G and return to tank In through the single conduit 9, the oil at lower temperatures may flow out of port H, through conduit 32 to one section of the reservoir tank. At a second predetermined temperature, see Figure 12, the port H will be closed and port J opened; whereupon, the oil will flow out through port J, through conduit 33 to a different section of the tank M. It is to be understood that at intermediate temperatures, or during a change of temperature, both ports H and J will be open and oil may return to the reservoir through both conduit 32 and 33. Figure 19 shows the control system and valve described above connected to the conventional oil cooler assembly.

In Figure 9, the modified system of Figure 7 is provided with a pressure relief valve 34 communicating with the inlet port A through conduit 35 and through conduit 36 with line 33 leading to the oil tank ill. However, the relief valve may be joined to the other tank line 32 by conduit 31, shown in dotted lines.

Figures 13, 14 and 15 show an arrangement of the valve shown in Figure 4 whereby the sleeve, or plug 3i is rotated instead of translated to re ister the ports. Ports on this valve have been lettered A, B, C, D, E, F, and G and perform similar functions'to those lettered A, B, C, D, E, F and G, respectively, of the valve shown in Figure 4. Thus, it is apparent that the valve shown in Figure 13 may be used in those circuits where the valve shown in Figure 4 has been used since it performs the same function.

Figures 16 and 17 show a rotary valve performing the same functions as that valve shown in Figure 10, the member 3| being rotated instead of translated to register with the ports. The ports are lettered A to J, corresponding to those lettered A to J in Figure 10, and perform similar functions. It is obvious that this valve arrangement may be used in place of that shown in Figure 10 in the various diagrams shown.

While the thermal elements 4 have been hown for purposes of illustration as spiral, the thermal elements can be of other well known types such as bellows, Sylphons or other elements translating temperature changes to motion.

To those skilled in the art. it will be evident that while the same thermostatic means may control these functions. the predetermined temperatures and routing of the outlet oil may be varied at will regardless of the sequence of operations of the main valve function.

Although the invention has been described and illustrated in connection with a cylindrical slide valve. the principles involved are susceptible of numerous other designs such as a rotation of a cylindrical valve element, instead of translation, and other means not necessarily circular in form. The invention is, therefore, limited only as indicated by the scope of the appended claims.

I claim as my invention:

1. In a temperature control device for a lubricant in a lubricating system, a lubricant oil valve. a by-pass, a lubricant cooler device comprising a warming section and a distinct core cooling section, communicating passages between the valve and the by-pass and the said sections, thermostatic means responsive to the temperature of the lubricant as it leaves the outlet port of the valve for operating the valve to selectively direct the flow of the lubricant through the by-pass, or the warming section, or the warming section and the core cooling section of the cooler device.

2. In a temperature control device for a lubricant in a lubricating system, a lubricant oil valve having an inlet and two outlets, a by-pass, a inbricant cooler device, the said device comprising a warming section and a separate core cooling section, communicating passages between the valve and by-pa'ss and the said sections, thermostatic means responsive to the temperature of the lubricant as it leaves the outlet port of the valve for operating said valve to selectively direct the flow of the lubricant through the by-pass, or the warming section, or the warming section and the core section of the cooler and to further selectively direct the flow through either or both of said valve outlets.

3. In a temperature control device for a lubricant in a lubricating system, a lubricant oil valve, a pressure relief valve, a by-pass, a lubricant cooler device, the said device comprising a warming section and a separate core cooling section, communicating passages between the valve and bypass, and the said sections, thermostatic nieans responsive to the temperature of the lubricant as it leaves the outlet port of the valve for operating said valve to selectively direct the flow of the lubricant through the by-pass, or the warming section, or the warming section and the core section of the cooler device and the relief valve being arranged between the inlet and the outlet to prevent excessive pressures in the warming and core sections.

4. In a temperature control device for lubricant in a, lubricating system, a lubricant oil valve having an inlet and two outlets, a relief valve, a by-pass, a lubricant cooler device, the said device comprising a warming section and a separate core cooling section, communicating passages between the valve and by-pass and the said sections, thermostatic means responsive to the temperature of the lubricant as it leaves the outlet port of the valve for operating said valve to selectively direct the flow of lubricant through the by-pass, or the warming section, or the warming section and the core section of the cooler, and to further selectively direct the flow through either.or both of the valve outlets,'the relief valve being arranged to prevent excessive pressure in the warming and core sections.

5. Oil conditioning apparatus including an oil cooler having a warming section and core, means to isolate the cooler with respect to oil pressures under one ondition of temperature and to direct oil to the cooler under another condition of temperature, comprising a valve having an inlet and an outlet, a by-pass including a closure therefor, said by-pass communicating with the inlet and outlet, a conduit including a closure therefor to conduct oil from the inlet to the warming section, a return conduit including a closure therefor to conduct oil from the warming section to the outlet, a second return conduit including a closure therefor to conduct oil from the core to the outlet, thermally responsive closure actuating means operable under said one condition to maintain all of the conduit closures in closed position and direct the oil flow through the by-pass, said closure actuating means operating under said other condition to maintain the by-pass closure in closed position and move the first-named conduit closure and one of said return conduit closures to open position to direct oil flow through the warming section alone or the warming section and the core.

6. Oil conditioning apparatus including an oil cooler having a warming section and a core, means to isolate the cooler with respect to oil pressures under one condition of temperature and to direct oil to the cooler under another condition of temperature, comprising a valve having an inlet and an outlet, a by-pass including a closure therefor, said by-pass communicating with the inlet and outlet, a conduit including a closure therefor to conduct oil from the inlet to the warming section, a return conduit including a closure therefor to conduct oil from the warming section to the outlet, a second return conduit including a closure therefor to conduct oil from the core to the outlet, thermally responsive closure actuating means operable under said one condition to maintain all of the conduit closures in closed position and direct the oil flow through the by-pass, said closure actuating means operating under said other condition to maintain the by-pass closure in closed position and move one of the return conduit closures to open position to direct oil fiow through the warming section alone or through the warming section and the core.

7. In combination, valve body means having inlet and outlet chambers, a main inlet port through which fluid enters the inlet chamber, a. main outlet port through which fluid leaves the outlet chamber, means which defines two paths by which fluid may pass from the inlet chamber to the outlet chamber including two ports in the inlet chamber and two ports in the outlet chamher, a fluid cooler communicating with one of said two ports in the inlet chamber and one of said two ports in the outlet chamber, and a bypass constructed to resist greater fluid pressures than said cooler and having substantially less flow resistance than said cooler communicating with the other of said two ports in the inlet chamber and the other of said two ports in the outlet chamber, port closure means movably mounted in said valve body including portions closing either and leaving open the other of said two ports in the inlet chamber, and portions closing either and leaving open the other of said two ports in the outlet chamber, and actuating means for said port closure means including a thermostat subjected to the temperature of the fluid in said outlet chamber and operable to move said .port closure means to direct fiuid selectively through one or the other of said paths and to open and close the port in said outlet chamber which communicates with said cooler proportionately to the clo:ing and opening of the port in said inlet chamber communicatin with said by-pass.

LESLIE T. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date Italy July 5, 1937 Number Number 

